Control logic for changing a multi-mode copier/duplicator from one mode to another

ABSTRACT

In a multi-mode automatic copier/duplicator designed to make copies of different sizes in different modes, a control apparatus is provided for completing a mode change automatically once the mode change is initiated by an operator and conditioning the machine to be ready to operate in the mode to which it is changed.

United States Patent 1191 Sohm 14 1 Sept. 30, 1975 CONTROL LOGIC FORCHANGING A MULTI-MODE COPIER/DUPLICATOR FROM ONE MODE TO ANOTHER [75]Inventor: Lawrence R. Sohm, Fairport, NY.

[73] Assignee: Xerox Corporation, Stamford,

I Conn,

[22] Filed: Nov. 29, 1974 [2]] Appl. N0.: 528,161

Related U.S. Application Data [63] Continuation of Ser. No. 393,544,Aug. 31, 1973,

abandoned.

[52] US. Cl. 355/8; 355/14; 355/49 [51} Int. Cl. 603G 15/22 [58] Fieldof Search '355/3 R, 8, 11, 14, 47-51 [56] References Cited UNITED STATESPATENTS- 3,450.995 6/1969 Hirsch 355/14 UX 3,480,360 11/1969 ,Mallory etal. 355/8 3,589,808 6/1971 Del Vecchio 355/3 R 3,652,157 3/1972 Blackertet al. 355/49 3,677,635 7 1972 Van Auken et a1. 355/51 x 3,689,1439/1972 Case et al. 355/3 R 3,740,132 6/1973 Komori et a1... 355/3 R3,833,296 9/1974 Vola et al. 355/51 FOREIGN PATENTS OR APPLICATIONS2,250,664 4/1973 Gemiany 355/8 OTHER PUBLICATIONS Hoskins et ali, DualMode Copying System, IBM Technical Disclosure Bulletin, June 1969, p.173.

Primary Examiner-Samuel S. Matthews Assistant Examiner-Kenneth C.Hutchison [5 7] ABSTRACT In a multi-mode automatic copier/duplicatordesigned to make copies of different sizes in different modes, :1control apparatus is provided for completing a mode change automaticallyonce the mode change is initiated by an operator and conditioning themachine to be ready to operate in the mode to which it is changed. 1

14 Claims, 16 Drawing Figures US. Patent Sept. 30,1975

Sheet 2 of 15 U.S. Pateznt Sept. 30,1975 Sheet30f 15 3,909,128

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U.S. Patent Sept. 30,1975 Sheet70f 15 3,909,128

EXPOSURE US. Patent Sept. 30,1975 Sheet80fl5 3,909,128

US. Patent Sept. 30,1975 Sheet 10 of 15 3,909,128

U.S. Patent SCpt. 30,1975 Sheet 12 of 15 3,909,128

F/G [3 MODE CHANGE END OF PLACE LDC INITIAL LEVER CTR RuN IN LDCPOSITION l COUNTER 2\ SCAN 2333",? SOLENOID PLATEN 20 I3 I /2\ HOME sCANMASTER GEARS To SWITCH SOLENOID CTR HELD LDC DRIVE DEACTIvATEDDEENERGIZED CLEAR ENGAGED l CAIGRJrIII'GEE PAwI 4\ LDC MODE END OFPREVENTS swITCH S6 sCAN FLYBACK OPENED END 0F 5\\ mm sw MOMENTARY s2swITCH s5 CLOSED oPERATEs I PAPER FEED l3 INHIBIT 6-\ VOLTAGE SOLENOID(+5v. DC) RELEASED PowER SUPPLY CTR START ENERGIzED "WAIT" LATCHED LIGHTOFF L D C "WAIT" //9 No Do I oGIC COMES CYCLE OUT INITIALIZED ON PAPERFEED SOLENOID INHIBITED US. Patent Sept. 30,1975 Sheet 15 0f15 3,909,128

LIGHT ome. 54T DEV. BIAS LATCH Y PRINT I [23 M CONTROL LOGIC FORCHANGING A MULTI-MODE COPlER/DUPLICATOR FROM ONE MODE TO ANOTHER FIELDOF THE INVENTION This is a continuation of application Ser. No. 393,544filed Aug. 31, 1973, now abandoned.

This invention relates to a copier/duplicator machine designed tooperate in different modes and more particularly, to a control apparatuswhich enables the machine to change from one mode to anotherautomatically once mode change is started.

BACKGROUND OF THE INVENTION Use of control circuitry for generatingsignals necessary to operate various devices or control elements in amachine is generally known. For example, xerographic copier/duplicatormachines based on Chester Carlsons invention in the electrostagographiccopying principles usually includes control means for implementingvarious steps involved in making xerographic copies; for example, meansfor charging a photosensitive insulating layer, imagewise exposing thelayer, developing the image with toner, transferring the image on asheet of paper, removing the sheet, heat fusing the transferred image onthe sheet, and cleaning the layer for subsequent use, etc. The means forachieving these steps include certain controlled elements forimplementing the various xerographic processing steps; for example,means responsive to a signal for actuating the main drive motor of themachine, common generating means for charging the photosensitiveinsulating layer or transferring the image on the layer onto thetransfer sheet or copy paper, magnetic brush developer means, means forcleaning the layer, scanner carriage and optical scanning means forprojecting the image of the original onto the photosensitive insulatinglayer, jam detection means, etc. The machine is usually provided with asuitable control logic circuitry for generating appropriate signalsrequired to actuate or energize. the various controlled elements in atimed sequence so that the xerographic steps are properly implemented.

Heretofore, generally the copier/duplicator was designed to operate in asingle mode in making copies of the original. For example, the typicalmachine was designed so that its optical scanning arrangement moved pastan original in a stationary position, or in the alternative, thescanning arrangement was held in a fixed or a stationary position whilethe document original was fed past the scanning arrangement in makingcopies up to a certain size. Such machines had an inherent limitation,in that, for example, they were capable of making copies only up to acertain given size, such as legal size paper (8 /2 inches X 14 inches),but not capable of making copies on a sheet which is larger than thisgiven size.

More recently, however, there has developed a copier/duplicator machinewhich is capable of operating in more than one mode of operation formaking copies of different sizes. An example of such a machine isdescribed in detail in the copending case, U.S. application Ser. No.284,687, filed on Aug. 29, 1972, now abandoned and replaced bycontinuation application Ser. No. 367,996, filed on June 7, 1973, bothapplications being assigned to the same assignee as the presentinvention. As described in the application, the machine is designed sothat in a first or base mode of operation a moving optical scanningmeans is used in scanning a stationary original and in a second or LDCmode of operation the scanning arrangement is stationary and thedocument original is moved past a scanning station by a document feedingmeans. The machine is designed so that, in the base mode, it can makecopies in normal letter size, (e.g., 8 /2 inches X l 1 inches) and up tolegal size (e.g., 8 /2X 14 inches) and in the LDC mode or Large DocumentCopy mode, copies up to 14 inches X 18 inches can be made.

SUMMARY OF THE INVENTION It is an object of the present invention toprovide control apparatus for enabling the machine to complete a modechanging operation automatically once a mode change is initiated.

It is another object of the present invention to provide improvedcontrol apparatus for completing a mode change in a copier/duplicatormachine capable of making copies of different sizes in different modesfrom the document originals of different sizes in a selective manner.

The foregoing and other objects of the present invention are achievedaccording to the present invention by providing a control apparatuswhich completes the mode change once the operator initiates the modechange.

It is another feature of the present invention to provide controlapparatus for generating signals necessary to control and complete amode changing operation.

It is still another feature of the present invention to provide controlapparatus having means for sensing that a machine is in the base mode,means for sensing that a document original feed means has been moved toan engaged position to be ready to feed a document original and meansresponsive to the movement of the document original feeding means to anengaged position for completing a mode change from the first or basemode to the second or LDC mode.

It is-a further feature of the present invention to provide controlapparatus for retaining scanning means at the end of a scan positionwhen the mode of operation is changed from the base mode LDC mode.

The foregoing and other objects and features of the present inventionwill be made clearer from the following detailed description of anillustrative embodiment of the present invention in conjunction with theaccompanying drawings, in which:

FIG. 1 shows a frontal schematic view of a copier/duplicator in whichcontrol circuitry according to the present invention may be utilized.

FIG. 2 shows a schematic top view of an auxiliary document originalfeeder that may be used as an accessory to the base machine when themachine is operated in the auxiliary or LDC mode.

FIG. 3 shows a perspective schematic view of the machine that showscertain switches and operator controlled elements involved in the modechanging operation of the machine.

FIG. 4 shows a functional block diagram of the control apparatus of thepresent invention.

FIG. 5 shows a functional block diagram of base logic that may be usedfor the base mode of operation of the control apparatus.

FIG. 6 11 when combined in the form of FIG. 12, show the auxiliarycontrol circuit in detail.

FIG. 13 shows an operational flow chart helpful in describing andunderstanding the operation of the condescribing and understanding theoperation of the control apparatus.

FIG. 16 shows a portion of the logic redrawn to show theinterrelationship of the LIGHT ORIGINAL and PRINT button on the LDClogic.

bEsckrprroN OF THE, ILLUSTRATIVE/ EMBODIMENT OF. THE PRESENT INVENTIONThe control circuitry of the present invention will be described in thecontext xerographic copier/duplicator machine of a specific design.However, it should be noted from the outset that although thedescription is in the context of the xerogrpahic machine, the scope ofthe present invention is not limited to the xerographic machine. Clearlyas will be evident from the following description,-the principles of thepresent invention can be applied to other types of machines havingsimilar operational requirements. Now referring to the drawings, asshown in FIG. 1, a xerographic copier/duplicator machine typicallyincludes various elements for implementing xerographic steps. Itcomprises a drum that may be driven clockwise about an axis 11. The drumincludes a photosensitive insulating layer surface 12 around theperiphery of which various controlled elements are situated; namely,charging means A, imagewise exposing means B, developing means C, imagetransfer D, cleaning means E, and fusing means F, etc., for effectingthe usual steps involved in making xerographic copies. The machine maybe further provided with a suitable feeding means PF for feeding copysheets of paper from a paper supply in a cassette 15 and a suitablepaper transfer means 17 for transferring the imaged paper onto thefusing station F where the toner image is fused onto the paper and thenpaper feed out to a suitable receptacle means 19.

As described in the copending application Ser. No. 367,996 mentionedabove, a subject xerographic copier/duplicator machine may be designedto operate in different modes. In a first, or base mode, conventionalsized documents up to a certain size are copied and in a second or LDCmode larger sized documents are processed. For example, in the basemode, the machine is designed to employ a moving optical scanningarrangement 21 24 to scan a stationary original placed on a platen 20 inmaking copies up to 14 inches in length and 8.5 inches in width. In theLDC mode, it is designed so that the scanning arrangement is held at astationary position and the document original is moved past a scanningstation SS.

Referring to FIGS. 1 3, in base mode operation, the scanning arrangement21 is moved across the width of the platen 20 by a carriage (not shown)so that the associated optical means 22 25 projects the image of theoriginal on the xerographic drum surface 12 at the image exposingstation B. In base mode operation, the machine is designed so that, ineach copy run after the initial warm-up period, each successivexerographic copying cycle is accomplished in the same given timeinterval. The cycle time starts as thescanning means leavesthe homeposition near the scan start sensing switch S1 and continues to movepast the platen and ends as it reaches the end of scan position at thescan end sensing switch S2. The next cycle begins as the scanning meansautomatically flies back to the home position.

In the LDC mode of operation, a large document original is fed through afeeding means 20 such as that shown in a pending U.S. application Ser.No. 205,911 filed on Dec. 8, 1971 or in U.S. Pat. No. 3,731,915 issuedto Guentner. For example, as shown in the forementioned copendingapplication Ser. No. 284,687, the document feeding means 30 may bestationed outside of the platen 20 and be in a disengaged position whenthe machine is to operate in the base mode as shown in dotted lines(FIG. 1). It includes a lever 31 which'is designed so that by moving itclockwise the feeding means 30 is brought into or engaged into aposition as shown in solid lines so that it can feed documents for theLDC Mode. Thus, in this position, the document original can be fed pastthe scanning station SS. A suitable mechanism 33 is provided in themachine for coupling feed rollers 34 to the main drive M when thedocument feeding means 30 is moved to the LDC position. Once engaged,the rollers 34 driven by the main drive M feeds the document original tothe left past the scanning station SS. The speed with which the paper isfed past the scanning station SS is synchronized with the speed withwhich the copy paper 36 from the paper cassette 15 is fed into atransfer relationship with the photosensitive insulating layer 12 by asuitable paper feeding means PF. When it is desired to operate themachine in the base mode, the document feeding means is simply moved outof the way of the platen by rotating the lever 31 in a counterclockwisedirection. The counter clockwise rotation of the lever 31 moves thedocument feeding means 30 to the right shown in dotted lines and out ofthe path of the scanning station SS. At the same time, the drivingmechanism 33 disengages the feed rollers 34 from the main drive M torender the document feeding means inoperative. While inthe illustrativeembodiment, it is shown that the document original feeding means ismoved from one position to another to engage or disengage the machine inthe LDC Mode, it need not be so limited. For example, the documentfeeding means could be held at a fixed stationary position usingsuitable actuating means such as a push button to engage or disengagedocument feed rollers and thus selectively engage the feeding means forthe LDC mode.

In the base mode, control circuitry of conventional design may be usedto provide signals necessary for the selective enabling of certainelements such as charging, exposing, developing, image transferring,fusing and cleaning means that implement the steps necessary in making acopy. The circuitry may comprise electromechanical or electroniccomponents such as that shown in the U.S. Pat. No. 3,301,126, as issuedto R.F. Osborne et al, on Jan. 31, 1967, or that shown in applicationser. No. 348,828, filed on Apr. 6, 1973. now U.S. Pat. No. 3,813,157,which acts to implement various xerographic process steps atappropriately timed intervals at various points in the processingoperation under conditions where necessary timing is derived from aclock or cam mechanism or other suitable means. Generally, as describedin the above mentioned copending application Ser. No. 367,996 for basemode operations,

the timing of the xerographic copying cycle is keyed to the scanningoperation of the scanning means. Thus, in the base mode, each cycle ofxerographic processing steps during the making of successive copies in a.copy run is keyed to the start and end of the scanning operationinvolving the movement of the scanning carriage between the homeposition (at switch S1 in FIG.1 or 3) and the end of scan position (atswitch S2 in FIG. 1 or 3).

. In addition, the control circuitry is also providedwith a suitabledesign such as that'shown in US. Pat. No. 3,588,472, as issued to ThomasH. Glaster et al. on June 28, 1971, or in US Pat. Ser. No..344,322,filed on Mar. 23', 1973, now US. Pat. No. 3,832,065, for detectingvarious malfunctions of the machine. For example, referring to FIGS. 1and 3, the machine may include detack detecting means 37 for detectingthe failure of copy paper separation from the drum surface 12, jamdetection means 38 for detecting a paper jam that may occur along thepaper path, and heat sensing element 39 for monitoring the temperatureof the fusing station F. The outputs of these detecting means form apart of the input signal to the control circuitry of the present system.

In the present machine, various sensing elements in the form of switchesare used to provide certain necessary input signals to the controlcircuitry. These switches are shown schematically in FIGS. 2 and 3, and,briefly stated, they provide the following functions:

S1 switch S1 is used for providing a signal indicative of the fact thatthe scanning element 21 is at the home or start position of the scancycle. This will be referred to, in the alternative, as a home switch,It is designed so that it is actuated when the scanning element 21 is atthe home position. In the actuated condition it is closed and providesground or a logic 0 signal.

S2 switch S2 is used to sense the positioning of the end scan positionas shown in FIGS. 1 and 3. This switch will be referred, in thealternative, as the end of scan switch. It is normally open but it isactuated to close when the scanning element 21 reaches the end of thescan position. When actuated it provides ground and a lo'gical'O signal.

S3 switch S3 (FIG. 3) is utilizedto detect the trailing edge of a copypaper sheet. It 'is normally closed. Upon detection of the trailingedge, it opens and provides a logical 1 signal.

54 switch S4 is utilized to sense the presence of a large size paper orLDC paper cassette in the paper tray. It is normally open. But it closesin the presence of a LDC paper cassette.

S5 switch S5 is positioned to sense the movement of the document feedingmeans 30 into the LDC mode position. It is normally in the open state.It is a a momentary switch that actuates or closes momentarily as thedocument feeding means 30 moves into the operative position for the LDCmode of operation. It is designedso that it initializes the controlcircuitry. S5 is connected so that when actuated, it momentarilyprovides +18 volts DC to a +5 volt D.C. regulator and triggers it intooperation, thereby supplying the necessary +5 volts DC to initialize orstart various circuit elements of the control circuitry. (FIG. 4). Themomentary switch S5 may be a one way rollover type switch that actuatesin a first direction when the'machine goes from the base mode to the LDCmode but not in the opposite direction. Switch S5 will be referred to asthe mode change switch alternatively.

S6 switch S6 is a step-wise switch-which is actuated to an opencondition as the document feeding means 30 moves to the LDC modeposition from base mode position. It is normally closed. Upon actuationto an open condition, it provides a logical 1 signal to the logiccircuit. The logic 1 signal from this switch is utilized 'by the LDCcontrol circuitry as an indication of the change in the mode ofoperation of the machine from the base mode to the LDC mode and of theoperation of the machine in the LDC mode. This switch willbe'alternatively referred to as LDC mode switch.

S7 and S8 these two switches are utilized to'sense leading'and trailingedges of the document original being fed into the documentfeeding means30. The

switches are normally closed and they are connected in series but theyopen in -the'presence of the document original to signify its presence.They are positioned in the path of the document original so that atleast one or the other will sense the presence of a paper of even anarrow width. Operation of either or both is utilized to signify thepresence of the document original, the leading and trailing edges of thedocument original.

Briefly stated, the switches S1 S8 above are connected to operate andprovide'the following functions.

The home switch S1 when actuated shows that the scan carriage is at'thehome position. The end of scan switch S2 is a non-actuated condition atthis point. Now suppose the operator wishes to operate the machine in anLDC or large document copy mode. The lever arm 31 is moved clockwise toplace the document feeding means 30 to the left and thereby place themachine in the large document copying mode. As the lever arm 31 isrotated, the LDC mode switch S6 is actuated and then the switch S5 ismomentarily actuated. This initializesthe control circuitry for the LDCmode of operation.

In response to such'initializing, the control circuitry causes thescanning arrangement and associated optics to move into the LDCposition, that is, to the end of the scan position associated withswitch S2. Furthermore, the control logic associated with LDC mode ofoperation is so designed that the action of copy paper feed solenoid IIin selectively feeding copy paper is prevented or inhibited 'while thescanning arrangement and the optics 21 25 move to the end of the scanposition. The arrival of the scanning elements at the end of the scanposition is sensed by the end of scan switch S2. Upon a detection ofthis condition by switch S2 the scanning and optic elements are retainedin the end of scan position by the enabling of a suitable pawl andratchet mechanism. For a detailed discussion of an exemplary mechanismof this type, one may refer to the copending application Ser. No.284,687. This prevents the scan carriage means from automaticallyreturning to the home switch position as done in base mode operationsand when the scanningmeans reaches the end of scan positiongthe maindrive M drives the document original feed rollers 34.

In response to the end of scan signal, the control circuitry removes theconstraints on the operation of the solenoid II to allow the copy paperfeeding means PF to selectively operate. With the solenoid enabled, thedrive belt means 41' and 42 are prevented from engaging with the maindrive M and no copy paper is fed. When solenoid II is de-actuated thecontrollogic, in response to actuation of the LDC document originalsensing means S7 and S8 as the document original passes thereby causesengagement of the drive belt means, and the main drive M is allowed todrive the copy paper feed rollers 44 in synchronism. with the speed withwhich the document original is fed past the scanning station SS. Theswitches S7 and S8 actuate as the document original paper is fedtherepast in the paper feeding means 30 and enables the control logic toproceed with LDC mode of copying operation. Absent any malfunction, themachine proceeds to complete the copying operation.

In the shut down phase of the LDC mode of operation, somewhat differentsteps are involved, as shall be more fully explained, depending uponwhether the trailing edge sensing switch S3 of the copy paper is sensedbefore or after the trailing edge of the document original is sensed bythe document original sensing switches S7 and S8.

There are a number of indicating means that may be provided in thecopier/duplicator machine, as shown in FIG. 3, to provide the followingfunctions: WAIT This is visual indication means 50. It is connected in amanner to provide the Wait indicia when the document feeding means 40 ismoved to the LDC position, and this condition is maintained by thecontrol circuitry until the scanning element 21 moves to the end of thescan position and the machine is ready to make copies. The lightedindicating means 50 comes to the view of the operator during this timeand alerts the operator to wait until the indication terminates beforethe document original sheet is fed through the feeding means 30. Theindicating means 50 may include a suitable notation WAIT for theoperators convenience. Preferably, the indicating means 50 may bepositioned above the console of the base machine as shown in FIG. 3 at aposition where it will be hidden by the housing of the paper feedingmeans 30 when the same is positioned for base mode operation.

ADD-PAPER An indicating means 51 Add Paper is provided to apprise anoperator that attention to the paper supply is necessary. It may be soconnected that it is energized by the control circuitry when the papersupply runs out or when the incorrect size paper supply is present.

CLEAR PAPER PATH The indicating means 52 is provided to signify to theoperator that a paper jam condition is present and requires clearing.

In addition, certain push buttons are provided in the machine forinputting certain command signals to the control circuitry. For example:

PRINT This input, button 53, is used to enable the operator to start themachine in the base mode or in the alternative in the LDC mode if themachine is already in the LDC mode.

LIGHT ORIGINAL This input, button 54, serves the function of starting anappropriate machine cycle when the original has poor background qualityand the operator wishes to remove the background and obtain a copy witha clearer background. If the machine is in the base mode, it may beplaced in the LDC mode by moving the lever arm clockwise; movement ofthe lever is accomplished by the operation of the momentary switch S5and LDC mode switch S6 to provide the print command signal. However, ifthe machine is already in the LDC mode then a depression of either thePRINT I button 53 or LIGHT ORIGINAL buttom 54 provides theprint commandsignal. a

STOP The STOP input, button 55, is used for stopping the machine in themiddle of its operation and causes the control circuitry to stop themachine at the end of the copying cycle in process.

The logic of the present control circuitry is configured so that whenoperated in the LDC mode, the machine operates in a single cycle or copymode, wherein one copy of a document original is made at a time. Thecopy cycle in an LDC mode is such that a copying cycle is started whenthe machine is placed in the LDC mode, the copy is formed and completedand thereafter a shutdown mode is initiated after a given delay. In eachcopy cycle in the present embodiment, a copy of up to a given size, forexample, 14 inches in length and 18 inches in width, is made. If theorginal is wider than 18 inches, then a succeeding cycle of the copyingprocess may be employed tocomplete the copying of the remainder of theorginal on a succeeding copy sheet.

Because of the flexibility and versatility built into the logic of thecontrol circuitry, the operation of the machine need not, however, belimited to that specifically set forth for the base and LDC modes ofoperation described above. For instance, the machine can be run so thatin theLDC mode, the machine may be employed as a single copy machine forsmall size copies ranging up to 8.5 inches in width and 14 inches inlength in size, although this mode is primarily designed to make largesized copy. The machine can also be run as a multicopy system in the LDCmode by provided a suitable means RDF (FIG. 1) designed to refeed adocument originalcoming out of the document feeding means 30 back toinput thereof before the machine is shut down by the control logic.

The general functions of the control circuitry according to the instantinvention are described with reference to the block diagram of FIG. 4.The control circuitry according to the present invention generallyincludes input means for applying various command or input-signals tothe control logic which are required to operate the machine either in abase mode or LDC mode. Another input means 61 is provided for applyingother required command or input signals to the control circuitry whenthe machine is operated in the LDC mode. The control circuitry is alsoprovided with base logic 62, LDC logic 63, and a buffer 64 for.selectively conveying output control signals from the base and LDC logicfor operating the controlled elements of the xerographic machine.

The input signals provided from input means 60 to the base logic 62include the manual command inputs 1 such as provided by the PRINT, LIGHTORIGINAL,

and STOP buttons, as well as sensor inputs such as provided by the homeposition scan switch S1, the copy paper edge sensing switch S3, thefailure condition detection means FD which includes the jam detectingmeans, the detackdetecting means, the means for sensing an over heatingof the fuser, etc., and machine interlock INTLK switch 63 which may beused to switch in or out on AC power source. These inputs are appliedfrom the input means 60 to the base logic 62 via suitable paths 64. Theinput signals provided from the input means 61 to the LDC logic 63include input sig-

1. A control apparatus in an automatic reproducing machine havingscanning means for scanning a stationary document original and documentoriginal feeding means for feeding a document original past saidscanning means while said scanning means is held stationary, saidmachine being designed to operate in a first mode wherein said scanningmeans is moved for scanning said stationary document original, and in asecond mode wherein said document original feeding means is positionedin an engaged position for feeding a document original past saidscanning means while it is held in said stationary position, comprising:mode change starting means including means for moving said documentoriginal feeding means from a disengaged position to said engagedposition, control circuitry including means responsive to the movementof said document original feeding means to said engaged position fromsaid disengaged position for completing said mode change operation byconditioning said machine so that said scanning means is held in saidstationary position, a plurality of reproducing step implementing means,means to set said machine in said first or said second mode, first meansresponsive to the setting of the machine in said first mode andresponsive to the starting operation for generating a plurality ofprocess step implementing signals, means for applying said process stepimplementing means for effecting the reproducing steps in said firstmode of operation, and Second means responsive to the setting of themachine in said second mode and responsive to the starting operation forgenerating a plurality of process step implementing signals and applyingsaid process step implementing signals to said plurality of means foreffecting the reproducing steps in said second mode of operation.
 2. Thecontrol apparatus according to claim 1, wherein said first meanscomprises a first circuit means and wherein said second means comprisesa second circuit means.
 3. The control apparatus according to claim 2,wherein said first circuit means is adapted to start and stop theoperation of said scanning means while said document original feedingmeans is held in a disengaged position, and said second circuit means isadapted to start and stop the operation of the reproducing steps uponthe detection of the leading edge and trailing edges of the documentoriginal being fed by said document original feeding means held in anengaged position while said scanning means is held in said stationaryposition.
 4. The control apparatus according to claim 3, wherein saidsecond circuit means is adapted to stop the operation of the machinewhen the trailing edge of document original is detected before thetrailing edge of the copy sheet is detected.
 5. The control apparatusaccording to claim 3, wherein said second circuit means is adapted toenable said machine to stop the operation when the trailing edge of copysheet is detected before the trailing edge of the document original isdetacted.
 6. The apparatus according to claim 3, including: means fordetecting the mode changeover from said first mode to said second modeand generating a changeover signal and means responsive to saidchangeover signal for automatically completing the changeover operationand enabling said means for generating said plurality of process stepimplementing signals.
 7. The control apparatus according to claim 6,wherein said machine includes a drive means for driving a plurality ofmoving parts of said machine, mode change starting means including levermeans for moving said document original feeding means to an engagedposition from a disengaged position for setting the machine in saidsecond mode, means for coupling said document original feeding means tosaid drive means as said document original feeding means is moved tosaid engaged position by said lever means, means for sensing themovement of said automatic document feeding means toward said engagedposition, means responsive to said movement for generating a mode changeorder signal indicative of a change from said first mode to said secondmode and a second mode status signal, and said second circuit meansbeing adapted to respond to said mode change order signal for completingthe mode change and to respond to said second mode status signal foroperating said machine in said second mode.
 8. The control apparatusaccording to claim 7, wherein in said first mode, said movable scanningmeans is returned to a home position after a scanning operation and setnormally, said mode change order signal enabling said machine to movesaid scanning means to the end of scan position, and means for retainingsaid scanning means at the end of said scan position in response to saidsecond mode status signal.
 9. The control apparatus according to claim8, including a DC power source, first sensing means for sensing saidscanning means being positioned at the home position and generating alogical signal of one state and generating a logical signal of oppositestate when said scanning means leaves the home position, second sensingmeans for providing a logical signal of one state when said documentfeeding means is in said disengaged position and changing said logicalsignal to its opposite state when said document feeding means is movedto said engaged position, third sensing means for sensing the movementof said document feeding means toward said engaged positiOn and adaptedto supply said DC power to said first and second logic means, saidsecond circuit means adapted to be responsive to the change of the stateof the output of said second sensing means to provide a signal forpreventing said copy sheet feeding means from feeding copy sheets andfor enabling said scanning means to move to the end of scan position,fourth sensing means sensing said scanning means reaching said end ofscan position, and means including said second circuit means responsiveto the output of said fourth sensing means for retaining said scanningmeans at the end of scan position, and conditioning said machine tooperate in said second mode.
 10. The control apparatus according toclaim 9 wherein said first, second and fourth sensing means includeswitches held in one state normally and said third sensing meansincludes a one-way roll-over switch.
 11. The control apparatus accordingto claim 10, including a visual indicating means, said second circuitmeans adapted to turn said indicating means off, said second circuitmeans being adapted to respond to the change in the output of said modechange sensing means to turn on said visual indication means, saidvisual indicating means including ''''WAIT'''' status lamp which lightswhen turned on, and said second circuit means being responsive to thechange in the output of said fourth sensing means for turning off saidvisual indicating means.
 12. The control apparatus according to claim10, wherein said second circuit means is responsive to said mode changesignal for causing said copy sheet feeding means to disengage from saiddrive means while said lever means is being moved to place said documentoriginal feeding means to said engaged position.
 13. The controlapparatus according to claim 1 wherein said apparatus is adapted toprovide said mode changing operation for said machine having means formaking copies of different sizes from different size document originalsselectively.
 14. The control apparatus according to claim 1 including anautomatic recirculating document feeder for automatically feeding thesame or different document originals in succession past the scanningmeans.